Paster roller

ABSTRACT

An air exhausting concave portion is provided on an outer peripheral surface of a paster roller that pushes a first web and a second web in their overlapped state. Both end portions of the outer peripheral surface of the paster roller are chamfered. The paster roller is formed like a crown shape.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a technology for jointing afirst web and a second web by pushing them in an overlapped state.

[0002] In a production line for a magnetic recording medium and otherstripe bodies, a web made of plastic, paper, metal foil, etc. isextracted from the a roller. Then predetermined processes, such ascoating, etc. are applied to the web.

[0003] In a related art, in order to exchange the web roller (oldroller) from which the web is pulled out and whose remaining amount ofthe web becomes small for the unused web roller (new roller), and inorder to stop the production line as few as possible, varioustechnologies were proposed.

[0004] For example, in JP-A-11-91997, a paper jointing system isdisclosed. The paper jointing system joints the rear end of the webwound on the old roller and the top end of the web wound on the newroller by overlapping them and pushing them by virtue of the brush.

[0005] Also, in JP-A-9-12185, the other conventional system isdisclosed. The system joints the rear end of the web on the old rollerfor the magnetic recording medium and the top end of the web on the newroller by pushing them by virtue of a paster roller (press roller orjoint roller).

[0006] In this system, when the remaining amount of the web on the oldroller is small, the new roller is rotated at a speed almost equal tothat of to the older roller. Then, while sensing the position of anadhesive tape on the new roller by a sensor provided in vicinity of thenew roller, the web of the old roller is pushed against the outerperipheral surface of the new roller at a predetermined timing by thepaster roller. As a result, the top end of the web on the new roller canbe jointed to the rear end of the web of the old roller via the adhesivetape on the new roller.

[0007] In the web jointing system, even when the web of the old rolleris pushed against the outer peripheral surface of the new roller by thepaster roller, there is a possibility that they are jointedinsufficiently by the adhesive tape in some cases. If the jointing bythe adhesive tape is insufficient, there are caused the disadvantagessuch that the web is broken down at the jointed location during thetransportation of the web, etc.

[0008] Also, in the web jointing system in the related art, when the webof the old roller is pushed against the outer peripheral surface of thenew roller by the paster roller, sometimes the web of the old roller iscut. Such cutting of the web causes the considerable reduction inproduction efficiency because the production line must be stopped to fixit.

SUMMARY OF THE INVENTION

[0009] The present invention has been made in view of the abovecircumstances, and an object of the present invention provides a pasterroller that is capable of pushing the second web against the first webfirmly and preventing the web cutting to contribute the improvement ofthe productivity.

[0010] The above object of the present invention can be achieved byproviding a paster roller comprising: an air exhausting concave portionprovided on an outer peripheral surface thereof for releasing an airbetween a first web and the outer peripheral surface, when the outerperipheral surface pushes the first web to a second web in theiroverlapped state.

[0011] Recently the thinning of the web such as the magnetic recordingmedium has been promoted. There is caused the case that, with suchthinning of the web, the behavior of the web of the old roller becomesunstable by an air between the paster roller and the web of the oldroller. That is, there is caused the case that the web of the old rollercannot be pushed uniformly against the outer peripheral surface of thenew roller because of the influence of this air. In particular, it isfound that, when the web carrying speed is high, there is such atendency that the web of the old roller cannot be pushed uniformlyagainst the outer peripheral surface of the new roller.

[0012] If the above structure of the present invention is employed, anair exhausting concave portion can be provided on an outer peripheralsurface of the paster roller. Therefore, when the paster roller is movedtoward the web of the old roller by the air cylinder, etc., an airbetween the paster roller and the first web can be removed from theconcave portion. In this manner, since the first web can be pusheduniformly against the second web by the paster roller, the first web andthe second web can be pushed surely even if the web carrying speed ishigh, and thus the firm web jointing can be attained.

[0013] In this case, the advantages of the present invention become moreremarkable if the web is thinner, and the advantages of the presentinvention become particularly remarkable if the thickness of the firstand second webs is 10 μm or less, preferably 7 μm or less. Also, theadvantages of the present invention become more remarkable if the webcarrying speed is relatively fast (e.g., 200 m/min or more).

[0014] Also, in the present invention, it is preferable that the spiralgroove should be provided on the outer peripheral surface of the pasterroller. Such groove can be formed by the simple machining and also canbe easily cleaned during the use of the paster roller. It is preferablethat the groove shape should be formed like the semi-circular shape orthe circular arc shape in section, but the rectangular shape may beemployed. The groove shape is not particularly limited. A groove pitchcan be set to 1 to 10 mm, for example. A groove depth can be set to 0.1to 1 mm, for example.

[0015] In addition, in the present invention, it is preferable that thepaster roller should be constructed to have a core bar and a coatedelastic body provided on the outer peripheral surface of the core bar.As the material of the coated elastic body, the resin such as the rubbermaybe employed, for example. The web supplying system (the web jointingsystem) into which the above paster roller is installed can beconstructed as follows. That is, the web supplying system comprises afirst shaft to which the old roller is installed, a second shaft whichis provided at a predetermined interval from the first shaft and towhich the new roller is installed, and the paster roller for pushing thewebs in the situation that the rear end of the web of the old roller andthe top end of the web of the new roller are overlapped, and an airexhausting concave portion is provided on the outer peripheral surfaceof the paster roller. The web supplying system can joint the rear end ofthe web of the old roller and the top end of the web of the new rollerby pushing the paster roller against them so as to supply the web of thenew roller subsequently to the web of the old roller.

[0016] The above object of the present invention can be achieved byproviding a paster roller comprising: chamfered portions formed at bothend portions of an outer peripheral surface thereof.

[0017] Here, it is preferable that the chamfered portions should containportions of the outer peripheral surface of the paster roller that areopposed to portions in the range from 20 mm to 50 mm from both endportions of the web, which contacts to the outer peripheral surface ofthe paster roller, in the width direction. In addition, the chamferedportion includes a flat portion that is inclined at a predeterminedinclination angle or as the curved surface in a sectional view. At thistime, the inclination angle relative to the center axis of the pasterroller should be set preferably to 3° or more and 20° or less, and morepreferably to 5° or more and 15° or less. In particular, 8° or more and12° or less is preferable.

[0018] Also, the connected portion between the chamfered portion andother portions on the outer peripheral surface of the paster roller maybe constructed to form the edge or to be connected smoothly without theedge.

[0019] An substantially cylindrical core bar or an substantially columncore bar can be employed as the core bar, for example. The aluminum,etc. can be exemplified as the material of the core bar, but thematerial of the core bar is not particularly limited to this.

[0020] The resin such as the rubber can be employed as the material ofthe coated elastic body. It is preferable that the coated elastic bodyshould have the hardness (HsA) in the range from 40 to 70, which ismeasured by the spring type hardness test (A type) defined in JIS(Japanese Industrial Standard) K6301. Also, HsA should be set higher ifthe web carrying speed is high.

[0021] As the result of the earnest examination made by the inventors ofthe present invention, it is found that the above cutting of the web iscaused bent paster roller. Namely, since the paster roller is bent whenthe paster roller is pushed against the outer peripheral surface of thenew roller via the web of the old roller, both end portions of thepaster roller in the axial direction impacts strongly against the web ofthe old roller. This is because that the cylinders provided near bothend portions of the paster roller, or the like are operated, when thepaster roller is pushed against the web of the old roller, and thereforethe bending moment becomes maximum in the center of the paster roller.

[0022] According to the above structure of the present invention, thepushing force acting to both end portions of the web in the widthdirection can be reduced, when the paster roller pushes against the weband thus the web is pushed over the entire range in the width directionby the substantially uniform pushing force. It is caused that both endportions of the paster roller in the axial direction, which impactstrongly against the web, are chamfered. Therefore, even if the pasterroller is pushed against the web of the old roller, both end portions inthe axial direction never hit strongly against the web of the old rollerand thus the cutting of the web can be prevented without fail. In thismanner, the improvement of the productivity can be achieved.

[0023] In this case, the advantages of the present invention become moreremarkable if the web is thinner. The web- cutting preventing effect ofthe present invention become particularly remarkable if the thickness ofthe first and second webs is 10 μm or less, particularly 7 μm or less.

[0024] The web supplying system into which the above paster roller isinstalled can be constructed as follows. That is, the web supplyingsystem comprises a first shaft to which an old roller is installed, asecond shaft which is provided at a predetermined interval from thefirst shaft and to which a new roller is installed, and a paster rollerfor pushing the webs in the situation that the rear end of the web ofthe old roller and the top end of the web of the new roller areoverlapped, and both end portions of the outer peripheral surface of thepaster roller are chamfered. The web supplying system can joint the rearend of the web of the old roller and the top end of the web of the newroller by pushing the paster roller against them so as to supply the webof the new roller subsequently to the web of the old roller.

[0025] The above object of the present invention can be achieved byproviding a paster roller for pushing the first web and the second webin their overlapped state, wherein the paster roller is formed as apredetermined crown shape. For examination, the predetermined crownshape is defined by rotating a bus-line having an inclination or curvethe height of which is changed by from 0.5 mm to 2.5 mm at a position1000 mm apart therefrom.

[0026] The crown shape signifies that the outer peripheral shape of thepushing portion of the paster roller, that pushes against the first andsecond webs, is formed as a barrel shape having a predetermined crown (adifference between an outer peripheral diameter of the center portion ofthe pushing portion and an outer peripheral diameter of both endportions in the axial direction). That is, this crown shape means such ashape that the pushing portion of the paster roller has the maximumouter peripheral diameter in the center portion in the axial direction,and the outer peripheral diameter is reduced gradually from the centerportion to both end portions in the axial direction, and the outerperipheral diameter becomes minimum in both end portions in the axialdirection.

[0027] It is preferable that a range of 0.5 mm or more and 2.5 mm orless per a width 1000 mm of the paster roller should be selected as thecrown.

[0028] The pushing portion of the paster roller is constructed to havethe core bar and the coated elastic body provided on the outerperipheral surface of the core bar, but is not limited to thisstructure.

[0029] The substantially cylindrical core bar or the substantiallycolumn core bar can be employed as the core bar, for example. Thealuminum, etc. can be exemplified as the material of the core bar, butthe material of the core bar is not particularly limited to thismaterial.

[0030] The resin such as the rubber can be employed as the material ofthe coated elastic body. It is preferable that the coated elastic bodyshould have HsA from 40 to 70. Also, HsA should be set higher if the webcarrying speed is high. If the above structure of the present inventionis employed, since the paster roller is formed like the substantiallycrown shape, the center portion of the paster roller in the axialdirection can push against the web when the paster roller is bent asabove, so that the paster roller can push against the web of the oldroller substantially uniformly over the entire range in the axialdirection. Therefore, even if the paster roller is pushed against theweb of the old roller, both end portions of the pushing portion in theaxial direction never hit strongly against the web of the old roller andthus the cutting of the web can be prevented without fail. Further, evenif the paster roller is pushed against the web by the weak force thatcannot joint the webs in the related art, the webs can be jointedsatisfactorily. In other words, since the force for pushing the pasterroller against the web can be transmitted substantially uniformly to theentire range in the axial direction, the extra force to correct theunevenness of the pushing force due to the bending of the paster rolleris not needed, and thus the webs can be satisfactorily jointed. In thismanner, the improvement of the productivity can be achieved.

[0031] In this case, the advantages of the present invention become moreremarkable if the web is thinner. The web-cutting preventing effect ofthe present invention become particularly remarkable if the thickness ofthe first and second webs is 10 μm or less, particularly 7 μm or less.

[0032] The web supplying system into which the above paster roller isinstalled can be constructed as follows. That is, the web supplyingsystem comprises a first shaft to which an old roller is installed, asecond shaft which is provided at a predetermined interval from thefirst shaft and to which a new roller is installed, and a paster rollerfor pushing the webs in the situation that the rear end of the web ofthe old roller and the top end of the web of the new roller areoverlapped, and the paster roller is formed like the crown shape. Theweb supplying system can joint the rear end of the web of the old rollerand the top end of the web of the new roller by pushing the pasterroller against them so as to supply the web of the new rollersubsequently to the web of the old roller.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033]FIG. 1 is a conceptual view showing a web supplying system towhich an embodiment of the present invention is applied;

[0034]FIG. 2 is a partial sectional view showing an embodiment of thepresent invention;

[0035]FIG. 3 is a schematic view showing another embodiment of thepresent invention;

[0036]FIG. 4 is a schematic view showing another embodiment of thepresent invention;

[0037]FIG. 5 is a schematic view showing another embodiment of thepresent invention; and

[0038]FIG. 6 is a schematic view showing another embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

[0039] Embodiments of the present invention will be explained in detailwith reference to the drawings hereinafter. FIG. 1 is a schematic viewof a web supplying system 10 for the magnetic recording medium, intowhich a paster roller 20 as an embodiment of the present invention isinstalled. As a web roller for the magnetic recording medium (newroller), such a web roller is employed that, for example, an outermostperipheral diameter is 500 mm, a web width is 1000 mm, a length ofrolled web is 8000 m, and a web thickness is 10 μm or less. It is ofcourse that there is no limit in these dimensions.

[0040] In this web supplying system 10, an old roller 1 a and a newroller 1 b are fitted to top ends of the three-axle turret arm 11 thatis rotatably supported. The turret arm 11 is not limited to the threeaxle type, and the two axle type, etc. may be employed. An adhesive tape2 such as the double-faced adhesive tape is provided to the outermostperipheral end portion of the web of the new roller 1 b. A sensor 13 forsensing the position of the adhesive tape 2 is provided in vicinity ofthe new roller 1 b. Also, the paster roller 20 is provided in vicinityof the new roller 1 b. The web of the old roller 1 a is passed betweenan outer peripheral surface of the new roller 1 b and an outerperipheral surface of the paster roller 20. Both the outer peripheralsurface of the new roller 1 b and the outer peripheral surface of thepaster roller 20 do not come into contact with the web of the old roller1 a.

[0041] When a remaining amount of the web on the old roller 1 a isreduced, the new roller 1 b is rotated at the similar speed to the oldroller 1 a. Then, while sensing the position of the adhesive tape 2 bythe sensor 13, the web of the old roller 1 a is pushed against theadhesive tape 2 on the outer peripheral surface of the new roller 1 b ata predetermined timing by the paster roller 20. The paster roller 20 isdriven by the cylinder actuator, or the like. At this time, in therelated art, there are the anxiety that the web of the old roller 1 acannot be pushed uniformly against the adhesive tape 2 on the outerperipheral surface of the new roller 1 b or the anxiety that the web iscut off. Nevertheless, in this web supplying system 10, such anxiety canbe eliminated since the paster roller 20 described later is employed.

[0042] As shown in FIG. 2, the paster roller 20 has an substantiallycylindrical core bar 21 made of aluminum, and a rubber (HsA in the rangefrom 40 to 70) 22 provided to an outer peripheral surface of the corebar 21. Then, a spiral groove 25 serving as an air exhausting concaveportion is provided in the substantially overall area of the outerperipheral surface of the rubber 22, i.e., the outer peripheral surfaceof the paster roller 20 in the axial direction.

[0043] A journal 23 is provided to both end portions that are projectedfrom both ends of the rubber 22 on the core bar 21. The journal 23 isrotatably supported by a bearing 28.

[0044] As shown in the enlarged portion in FIG. 2, the groove 25 has ansubstantially semi-circular shape in section. A groove pitch is set to 1to 10 mm. A groove depth D is set to 0.1 to 1 mm. This groove 25 can beformed by one grooving operation by using the cutting tool, the turningtool, etc. Also, this groove 25 is easily cleaned.

[0045] For example, an axial dimension L of the rubber 22 can be set to1200 mm that is slightly larger than the web width. Of course, thisdimension is not particularly limited. However, it is preferable that,as described above, the dimension L should be set larger than the webwidth. This is because, if the roller end portion hits on the productsurface of the old roller, it is possible that the portion becomes nogood.

[0046] If the above paster roller 20 is moved toward the web of the oldroller 1 a shown in FIG. 1 by the air cylinder, etc., the air betweenthe paster roller 20 and the web of the old roller 1 a can be exhaustedsmoothly from the groove 25 on the outer peripheral surface of thepaster roller 20. Therefore, the web of the old roller 1 a can be pusheduniformly against the adhesive tape 2 on the outer peripheral surface ofthe new roller 1 b by the paster roller 20. The paster roller 20 isrotated together with the rotation of the new roller 1 b when it isbrought into contact with the outer peripheral surface of the new roller1 b via the web of the old roller 1 a. At this time, since the groove 25is formed spirally, the groove position at the contact surface betweenthe paster roller 20 and the web of the old roller 1 a (the position atwhich the web of the old roller 1 a is not pushed by the paster roller20) is shifted with the rotation of the paster roller 20 in the axialdirection of the paster roller. For this reason, the web of the oldroller 1 a can be pushed substantially uniformly by the paster roller 20to leave no space.

[0047] According to the present structure, even if the web carryingspeed is large, the rear end of the old roller 1 a and the top end ofthe new roller 1 b can be jointed without fail. The improvement of theproductivity can be achieved by such web supplying system 10.

[0048]FIGS. 3A to 3D are a schematic view showing paster rollers 30, 40,50, 60 as another embodiment of the present invention respectively.

[0049] In a paster roller 30 shown in FIG. 3A, differently-directedspiral grooves 35 a, 35 b are provided on one side area and the otherside area with respect to the center portion of the outer peripheralsurface of a rubber 32 in the axial direction respectively. The grooves35 a, 35 b are, so to speak, line symmetry. According to the pasterroller 30 in which such bilaterally symmetrical grooves 35 a, 35 b areprovided, the first web and the second web can be pushed uniformly.

[0050] In a paster roller 40 shown in FIG. 3B, a plurality of ring-likegrooves 45 are provided at an equal distance to extend the overall areaof the outer peripheral surface of a rubber 42 in the axial direction.According to the paster roller 40 in which such grooves 45 are provided,the first web and the second web can be pushed uniformly.

[0051] In a paster roller 50 shown in FIG. 3C, a plurality of slits 55as the concave portion are provided at a distance to predeterminedlocations of a rubber 52 in the axial direction. A core bar 51 may beexposed from the locations at which the slits 55 are provided. Accordingto the paster roller 50 in which such slits 55 are provided, the web canbe adapted itself to the outer peripheral shape of the new roller andthus the first web and the second web can be pushed uniformly.

[0052] In a paster roller 60 shown in FIG. 3D, a very large number ofdimples 65 are provided over the entire area of the outer peripheralsurface of a rubber 62 in the axial direction. According to the pasterroller 50 in which such dimples 65 are provided, the first web and thesecond web can be pushed uniformly. Also, the dimples 65 may be formedto be connected mutually.

[0053]FIG. 4 shows a paster roller as still another embodiment of thepresent invention. As shown in FIG. 4, a paster roller 120 has thesubstantially cylindrical core bar 21 made of aluminum, and a rubber(HsA in the range from 40 to 70) 122 as a coated elastic body providedto the outer peripheral surface of the core bar 21. A diameter D3 of theouter peripheral surface of the core bar 21 is uniform. The journal 23is provided to both end portions that are projected from both ends ofthe rubber 122 on the core bar 21. The journal 23 is rotatably supportedby the bearing 28. The outer peripheral surface of the rubber 122consists of a cylindrical surface portion 122 a, that is located in thecenter portion in the axial direction and has a outer peripheraldiameter D1, and chamfered portions 122 b, that are positioned adjacentto both end portions of the cylindrical surface portion 122 a in theaxial direction and are inclined at a predetermined inclination angle.In order to illustrate the position at which the chamfered portions 122b are formed, the situation that the web W contacts to the outerperipheral surface of the cylindrical surface portion 122 a of therubber 122 is shown by a chain double-dashed line.

[0054] One end portion of the web W (left side in FIG. 4) in the widthdirection and the rubber 122 that contacts to the area near the endportion are shown in detail in the enlarged portion in FIG. 4. Thechamfered portion 122 b is chamfered at an inclination angle θ from aconnected portion C1 that is separated by a distance d from the endportion of the web W in the width direction to the inner direction ofthe web (rightward direction in the enlarged portion in FIG. 4), whenthe web W is brought into contact with the outer peripheral surface ofthe cylindrical surface portion 122 a. That is, the outer peripheralsurface of the chamfered portion 122 b is inclined rather than the outerperipheral surface of the cylindrical surface portion 122 a to the corebar 21 side.

[0055] For example, the conditions that the dimension L of the rubber122 in the axial direction is 1100 mm, the diameter D1 of the outerperipheral surface of the cylindrical surface portion 122 a of therubber 122 is 100 mm, the diameter D3 of the outer peripheral surface ofthe core bar 21 is 80 mm, the distance d from the end portion of the webto a starting point of the chamfered portion 122 b is 50 mm, and theinclination angle θ of the chamfered portion 122 b is 10° may beemployed. But it is of course that there is no limitation of thedimension. However, it is preferable that, as described above, thedimension L should be set larger than the web width. This is because, ifboth end portions of the paster roller hit on the product surface of theold roller, it is possible that the portion becomes No Good. Also, it ispreferable that the connected portion C1 of the outer peripheralsurfaces of the cylindrical surface portion 122 a and the chamferedportion 122 b should be constructed not to form the edge.

[0056] According to the paster roller 120 described above, both endportions of the paster roller 120, that hit strongly onto the web W whenthe web W is pushed, in the axial direction, are formed as the chamferedportion 122 b. Therefore, the pushing force acting to both end portionsof the web W in the width direction can be reduced, and thus the web Wcan be pushed by the substantially uniform pushing force over theoverall area of the web W in the width direction. As a result, even ifthis paster roller 120 is pushed against the web of the old roller, bothend portions are never strongly brought into contact with the web of theold roller, and thus the cutting of the web can be prevented withoutfail. In this manner, the improvement of the productivity can beachieved.

[0057]FIG. 5 shows a paster roller 130 as yet still another embodimentof the present invention. The paster roller 130 has the substantiallycylindrical core bar 21 made of aluminum, and a rubber (HsA in the rangefrom 40 to 70) 132 as a coated elastic body provided to the outerperipheral surface of the core bar 21. The rubber 132 consists of acylindrical surface portion 132 a having an outer peripheral diameterD1, and gently-curved chamfered portions 132 b positioned adjacent toboth end portions of the cylindrical surface portion 132 a in the axialdirection. Connected portions C2 between the cylindrical surface portion132 a and the chamfered portions 132 b are connected smoothly not toform edges on the outer peripheral surface.

[0058] Since no edge is formed on the outer peripheral surface of therubber 132 in the paster roller 130 constructed as above, the pressureis never partially concentrated to the web when the paster roller 130 isinstalled into the above web supplying system 10 (see FIG. 1) and ispushed against the web. Accordingly, the cutting of the web can beprevented firmly.

[0059] In this case, other structures and operations not explainedherein are similar to the above embodiment shown in FIG. 4.

[0060]FIG. 6 shows a paster roller as yet still another embodiment ofthe present invention. As shown in FIG. 6, a paster roller 220 has thesubstantially cylindrical core bar 21 made of aluminum, and a rubber(HsA in the range from 40 to 70) 222 as the coated elastic body providedto the outer peripheral surface of the core bar 21. Then, the diameterD1 of the outer peripheral surface of the rubber 222 in the centerportion in the axial direction is formed larger than a diameter D2 ofthe outer peripheral surface in both end portions in the axialdirection. In more detail, the rubber 222 has a crown shape in which thediameter D1 of the outer peripheral surface in the center portion in theaxial direction becomes maximum. That is, the diameter of the outerperipheral surface of the rubber 222 is gradually increased from bothend portions to the center portion in the axial direction. Then, theouter peripheral surface is smoothly connected in the center portion inthe axial direction, so that no edge is formed at the connected portionon the outer peripheral surface.

[0061] The diameter D3 of the outer peripheral surface of the core bar21 is uniform. The journal 23 is provided to both end portions that areprojected from both ends of the rubber 222 on the core bar 21. Thejournal 23 is rotatably supported by the bearing 28.

[0062] For example, the conditions that the dimension L of the rubber222 in the axial direction is 1100 mm, the diameter D1 of the outerperipheral surface of the center portion the rubber 222 in the axialdirection is 100 mm, the diameter D2 of the outer peripheral surface ofboth end portions of the rubber 222 in the axial direction is 98.5 mm,and the diameter D3 of the outer peripheral surface of the core bar 21is 80 mm may be employed. But it is of course that there is nolimitation of the dimension. However, it is preferable that, asdescribed above, the dimension L should be set larger than the webwidth. This is because, if both end portions of the paster roller hit onthe product surface of the old roller, it is possible that the portionbecomes No Good.

[0063] Since the outer peripheral shape of the rubber 222 is formed likethe crown shape in the mentioned-above paster roller 220, the centerportion of the rubber 222 in the axial direction can push against theweb when the paster roller 220 is bent, so that the rubber 222 can pushagainst the web of the old roller 1 a (see FIG. 1) substantiallyuniformly over the entire area of the rubber 222 in the axial direction.As a result, if the paster roller 220 is pushed against the web of theold roller 1 a, both end portions of the rubber 222 in the axialdirection never strongly contact to the web of the old roller 1 a,whereby the web cutting can be prevented without fail. In addition, evenwhen the paster roller 220 is pushed against the web by the weak forceby which the webs cannot be jointed in the related art, the webs can bejointed satisfactorily. That is, because the force for pushing thepaster roller 220 against the web can be transmitted substantiallyuniformly to the overall area of the rubber 222 in the axial direction,there is no need that the extra force should be applied to correct theunevenness of the pushing force because of the bending of the pasterroller 220, and thus the webs can be jointed satisfactorily. In thismanner, the improvement of the productivity can be achieved.

[0064] The present invention is not limited to above embodiments, andappropriate variation, improvement, etc. may be applied. The aboveembodiments may be combined together.

[0065] For example, the air exhausting effect maybe accelerated byapplying the chemical surface process to the outer peripheral surface ofthe paster roller.

[0066] For example, the inner peripheral surface of the hollowcylindrical core bar may be supported by the reinforcing member. Also,the rubber may be formed integrally with the member constituting thecore bar 21.

EXAMPLES Test 1

[0067] The web roller on which the web made of PET (polyethyleneterephthalate) film, whose web width is 1000 mm and whose web thicknessis 6 μm, is rolled. On the outer peripheral surface of the web roller,the ultra-low pressure prescale is rolled was fitted to the websupplying system 10 as the new roller 1 b shown in FIG.1. Also, the sameweb roller on which the prescale is not rolled was fitted as the oldroller 1 a, and then the web was supplied by the feeding tension of 100N/m at the speed of 200 m/min.

[0068] In addition, as the paster roller, there were prepared two typepaster rollers in which, in the paster roller 120 shown in FIG.4, thedimension L of the rubber 122 in the width direction is set to 1100 mm,the hardness of the rubber 122 is set to HsA 60, the diameter D3 of theouter peripheral surface of the core bar 21 is set to 80 mm, and thedistance d from the end portion of the web to the connected portionbetween the cylindrical surface portion and the chamfered portion is 50mm, but the inclination angle of the chamfered portion is changed.

[0069] Out of two type paster rollers, the paster roller having theinclination angle θ of 10° was set as Example 1 and the paster rollerhaving the inclination angle θ of 5° was set as Example 2.

[0070] The paster roller of Example 1 or Example 2 was installed intothe above web supplying system, and then the pushing pressure of thepaster roller acting to the outer peripheral surface of the new rolleror the cylinder pressure was measured while pushing the paster rolleragainst the new roller via the web supplied from the old rollerrespectively and also the web on the old roller was watched andevaluated.

[0071] At this time, by way of comparison, the similar watch andevaluation were executed by using the paster roller that has theconventional cylindrical outer peripheral surface in which the chamferedportion is not formed.

[0072] In the test using the paster roller of Example 1, by setting thecylinder pressure acting to the paster roller to 300 kPa, the maximumvalue and the minimum value of the pushing pressure acting to the outerperipheral surface of the new roller were measured. Also the web of theold roller was watched. The case where the conventional paster rollershown as Comparative Example 1 is employed was watched under the similarcondition (the cylinder pressure 300 kPa).

[0073] In addition, in the test using the paster roller of Example 2, asthe condition not to cause the cutting of the web, the cylinder pressureto provide the maximum value 980 kPa of the pushing pressure acting tothe outer peripheral surface of the new roller and the minimum value ofthe pushing pressure were measured, and also the jointed state betweenthe web of the old roller and the web of the new roller was watched.Also, as to the conventional paster roller shown as Comparative Example2, the similar watching was executed at the maximum value of the pushingpressure to 980 kPa.

[0074] Results of the above evaluation test are given in Table 1. TABLE1 Comparative Comparative Example 1 Example 1 Example 2 Example 2Inclination 10 0 5 0 angle (degree) Cylinder 300 300 200 100 pressure(kPa) Pushing 1180 2350 980 980 pressure MAX (kPa) Pushing 880 880 680490 pressure MIN (kPa) Pushing 300 1470 300 490 pressure MAX-MIN (kPa)Situation Good Cut Good Adhesive peeling off Evaluation Good No GoodGood No Good

[0075] As shown in Table 1, according to the paster roller shown inExample 1, the maximum value of the pushing pressure acting to the outerperipheral surface of the new roller was 1180 kPa, the minimum value was880 kPa, and the difference between them was 300 kPa. Then, thedistribution of the pushing pressure of the paster roller acting to theouter peripheral surface of the new roller became minimum in the centerportion of the paster roller in the width direction, and was increasedtoward both ends in the axial direction, and became maximum at both endportions in the axial direction. Also, the cutting of the web suppliedfrom the old roller did not appear.

[0076] In contrast, according to the paster roller shown in ComparativeExample 1, the maximum value of the pushing pressure acting to the outerperipheral surface of the new roller was 2350 kPa, the minimum value was880 kPa. The difference between the maximum value and the minimum valuewas 1470 kPa, and the cutting of the web supplied from the old rollerappeared. In this case, the distribution of the pushing pressure of thepaster roller acting to the outer peripheral surface of the new rollerwas similar to Example 1.

[0077] Based on the results described above, according to the pasterroller shown in Example 1, the maximum value of the pushing pressureacting to the outer peripheral surface of the new roller was reduced to1170 kPa in contrast to 2350 kPa of the paster roller in the relatedart. Therefore, according to Example 1, the pushing pressure to the endportions of the web in the width direction could be reduced and thus theweb was never cut. In addition, according to this Example 1, thedifference between the maximum value and the minimum value of thepushing pressure could be reduced to 300 kPa in contrast to 1470 kPa ofthe paster roller in the related art. Therefore, according to Example 1,since the pushing pressure to the end portions of the web in the widthdirection was reduced, the pushing pressure acting to the web in thewidth direction became substantially uniform and thus the web of the oldroller and the web of the new roller could be satisfactorily jointedwithout the cutting of the web.

[0078] Also, as shown in Table 1, according to the paster roller shownin Example 2, the cylinder pressure was 200 kPa, the minimum value ofthe pushing pressure acting to the outer peripheral surface of the newroller was 680 kPa, and the web of the old roller and the web of the newroller could be satisfactorily jointed. The distribution of the pushingpressure acting to the outer peripheral surface of the new roller wassimilar to Example 1.

[0079] In contrast, according to the paster roller shown in ComparativeExample 2, the cylinder pressure was 100 kPa, the minimum value of thepushing pressure acting to the outer peripheral surface of the newroller was 490 kPa, and the web of the new roller could not besatisfactorily jointed to the web of the old roller. In this case, thedistribution of the pushing pressure acting to the outer peripheralsurface of the new roller was similar to Example 1.

[0080] Based on the results described above, according to the pasterroller shown in Example 2, the cylinder pressure could be increased twotimes rather than Comparative Example 2 and the minimum value of thepushing pressure could be increased without the increase of the maximumvalue of the pushing pressure. Therefore, since the difference betweenthe maximum value and the minimum value of the pushing pressure actingto the outer peripheral surface of the new roller could be reduced to300 kPa in contrast to 490 kPa in Comparative Example 2, the force forpushing the paster roller 20 against the web could be transmittedsubstantially uniformly to the overall area of the rubber 122 in theaxial direction. As a result, even if the cylinder pressure wasincreased to correct the unevenness of the pushing force due to thebending of the paster roller, the web of the old roller and the web ofthe new roller could be jointed satisfactorily without the increase ofthe maximum value of the pushing pressure.

Test 2

[0081] The web roller on which the web made of PET film, whose web widthis 1000 mm and whose web thickness is 6 μm, is rolled. On the outerperipheral surface of the web roller, the ultra-low pressure prescale isrolled. The web roller was installed into the web supplying system 10 asthe new roller 1 b shown in FIG. 1. Also, the same web roller on whichthe prescale is not rolled was installed as the old roller 1 a, and thenthe web was supplied by the feeding tension of 98 N/m at the speed of200 m/min.

[0082] In addition, as the paster roller, there were prepared two typepaster rollers in which, in the paster roller 220 shown in FIG.6, thedimension L of the rubber 222 in the width direction is set to 1100 mm,the hardness of the rubber 222 is set to HsA of 60, the diameter D3 ofthe outer peripheral surface of the core bar 21 is set to 80 mm, and thecrown is changed.

[0083] Any one of two type paster rollers, the one paster roller inwhich the crown is 1.5 mm (the maximum outer peripheral diameter D1:φ100 mm, and the minimum outer peripheral diameter D2: φ98.5 mm) was setas Example 3, and the other paster roller in which the crown is 0.5 mm(the maximum outer peripheral diameter D1: φ100 mm, and the minimumouter peripheral diameter D2: φ99.5 mm) was set as Example 4.

[0084] The paster roller of Example 3 or Example 4 was installed intothe above web supplying system, and then the pushing pressure of thepaster roller acting onto the outer peripheral surface of the new rollerwas measured while pushing the paster roller against the new roller viathe web supplied from the old roller respectively and also the web onthe old roller was watched and evaluated.

[0085] At this time, by way of comparison, the similar watching andevaluation were executed by using the paster roller that has theconventional cylindrical outer peripheral surface.

[0086] In the test using the paster roller of Example 3, by setting thecylinder pressure acting to the paster roller to 294 kPa, the maximumvalue and the minimum value of the pushing pressure acting to the outerperipheral surface of the new roller were measured. Then, the web of theold roller was watched. Also, the case where the conventional pasterroller shown as Comparative Example 3 is employed was watched under thesimilar condition (the cylinder pressure 294 kPa).

[0087] In addition, in the test using the paster roller of Example 4,the maximum value and the minimum value of the pushing pressure actingto the outer peripheral surface of the new roller were measured bysetting the cylinder pressure to 196 kPa. The jointed state between theweb of the old roller and the web of the new roller was watched. Also,as to the conventional paster roller shown as Comparative Example 4, thesimilar watching was executed at the same cylinder pressure.

[0088] Results of the above evaluation test are given in Table 2. TABLE2 Comparative Comparative Example 3 Example 3 Example 4 Example 4 Crown1.5 0 0.5 0 Cylinder pressure 294 294 196 196 (kPa) Pushing pressure 9801470 880 980 MAX (kPa) Pushing pressure 880 780 680 490 MIN (kPa)Pushing pressure 100 690 200 490 MAX-MIN (kPa) Situation Good Cut GoodAdhesive peeling off Evaluation Good No Good Good No Good

[0089] As shown in Table 2, according to the paster roller shown inExample 3, the maximum value of the pushing pressure acting to the outerperipheral surface of the new roller was 980 kPa, the minimum value was880 kPa, and the difference between them was 100 kPa. Then, thedistribution of the pushing pressure of the paster roller acting to theouter peripheral surface of the new roller became minimum in the centerportion of the paster roller in the width direction, and was increasedtoward both ends in the axial direction, and became maximum at both endportions in the axial direction. Also, the cutting of the web suppliedfrom the old roller did not appear.

[0090] In contrast, according to the paster roller shown in ComparativeExample 3, the maximum value of the pushing pressure acting to the outerperipheral surface of the new roller was 1470 kPa, the minimum value was780 kPa, the difference between the maximum value and the minimum valuewas 690 kPa, and the cutting of the web supplied from the old rollerappeared. In this case, the distribution of the pushing pressure actingto the outer peripheral surface of the new roller was similar to Example3.

[0091] Based on the results described above, according to the pasterroller shown in Example 3, the difference between the maximum value andthe minimum value of the pushing pressure acting to the outer peripheralsurface of the new roller could be reduced to 100 kPa in contrast to 690kPa of the paster roller in the related art. Therefore, according toExample 3, the pushing pressure acting to the web in the width directionbecame substantially uniform, and thus the web of the old roller and theweb of the new roller could be satisfactorily jointed without thecutting of the web.

[0092] Also, as shown in Table 2, according to the paster roller shownin Example 4, the cylinder pressure was 200 kPa, the maximum value ofthe pushing pressure acting to the outer peripheral surface of the newroller was 880 kPa, the minimum value was 680 kPa, and the differencebetween them was 200 kPa. The web of the old roller and the web of thenew roller could be satisfactorily jointed. In this case, thedistribution of the pushing pressure acting to the outer peripheralsurface of the new roller was similar to Example 3.

[0093] In contrast, according to the paster roller shown in ComparativeExample 4, the maximum value of the pushing pressure acting to the outerperipheral surface of the new roller was 980 kPa, the minimum value was490 kPa, and the difference between the maximum value and the minimumvalue was 490 kPa. The web of the new roller could not be jointedsatisfactorily to the web of the old roller. In this case, thedistribution of the pushing pressure acting to the outer peripheralsurface of the new roller was similar to Example 3.

[0094] Based on the results described above, according to the pasterroller shown in Example 4, the difference between the maximum value andthe minimum value of the pushing pressure acting to the outer peripheralsurface of the new roller could be reduced to 200 kPa in contrast to 490kPa in Comparative Example 4. Therefore, the force for pushing thepaster roller 20 against the web could be transmitted substantiallyuniformly to the overall area of the rubber 22 in the axial direction.As a result, the application of the extra force to correct theunevenness of the pushing force due to the bending of the paster roller20 was not needed, and also the web of the old roller and the web of thenew roller could be satisfactorily jointed by the small pushingpressure.

[0095] As described above, according to the present invention, thepaster roller that is capable of pushing the second web against thefirst web firmly and preventing the web cutting to contribute theimprovement of the productivity can be provided.

[0096] While only certain embodiments of the invention have beenspecifically described herein, it will apparent that numerousmodifications may be made thereto without departing from the spirit andscope of the invention.

What is claimed is:
 1. A paster roller comprising: an air exhaustingconcave portion provided on an outer peripheral surface thereof forreleasing an air between a first web and the outer peripheral surface,when the outer peripheral surface pushes the first web to a second webin their overlapped state.
 2. The paster roller as set forth in claim 1,wherein the air exhausting concave portion comprises a spiral grooveprovided on the outer peripheral surface of the paster roller.
 3. Thepaster roller as set forth in claim 2, wherein the groove has a pitch inthe range from 1 mm to 10 mm, and a depth on the range from 0.1 mm to 1mm.
 4. A paster roller comprising: chamfered portions formed at both endportions of an outer peripheral surface thereof.
 5. The paster roller asset forth in claim 4, wherein the chamfered port ions contain portions of the outer peripheral surface of the paster roller that are opposed toportions in the range from 20 mm to 50 mm from both end portions of theweb, which contacts to the outer peripheral surface of the pasterroller, in the width direction.
 6. The paster roller as set forth inclaim 4, wherein each of the chamfered portions includes a flat portionthat is inclined at a predetermined inclination angle ranged from 3° to20° relative to the center axis of the paster roller in a sectionalview.
 7. The paster roller as set forth in claim 4, further comprising:a core bar formed a substantially cylindrical shape; and a coatedelastic body provided on the outer peripheral surface of the core bar.8. The paster roller as set forth in claim 7, wherein the core bar ismade of aluminum.
 9. The paster roller as set forth in claim 7, whereinthe coated elastic body is made of resin, and the coated elastic bodyhas hardness (HsA) in the range from 40 to
 70. 10. A paster roller forpushing a first web and a second web in their overlapped state, whereinthe paster roller is formed into a crown shape, and the paster rollerhas a predetermined crown.
 11. The paster roller as set forth in claim10, wherein the predetermined crown has a range from 0.5 mm to 2.5 mmper a width 1000 mm of the paster roller.
 12. The paster roller as setforth in claim 10, further comprising: a core bar formed a substantiallycylindrical shape; and a coated elastic body provided on the outerperipheral surface of the core bar for pushing portion of the pasterroller.
 13. The paster roller as set forth in claim 12, wherein the corebar is made of aluminum, the coated elastic body is made of resin, andthe coated elastic body has hardness (Has) in the range from 40 to 70.